Are there some specific situations when the X0xb0x goes haywire? Or does it do strange things when you just play single, non overlapped notes too?
From the top of my head, your OT might be sending some midi data that the X0xbox doesn’t understand. Turn off everything else except midi sync-related options, like program changes and stuff.
Another explanation might be that your OT sample tracks share the same midi channel as the X0xbox, then OT’s sending all kinds of crap to the X0xb0x, which goes nuts with too much information. Just change the midi channel to a free one.